package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker
{
    //开始的时间戳 2022-01-01
    private static final long BEGIN_TIMESTAMP = 1640995200L;
    private static final long COUNT_BITS = 32L;

    private StringRedisTemplate stringRedisTemplate;

    public RedisIdWorker(StringRedisTemplate stringRedisTemplate)
    {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public long nextId(String keyPrefix)
    {
        //1.生成的时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timeStamp = nowSecond - BEGIN_TIMESTAMP;

        //2.生成序列号
        //2.1获取当前日期，精确到天
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));

        //2.2自增长
        long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" +date);

        //3.拼接并返回
        return timeStamp << COUNT_BITS | count;
    }

}
